Andrea,

I have a similar problem and came up with a (mostly) complete solution. I
used elscreen and added the ability to bind a set of buffers to a screen. It
tries its best to hide the buffers from the list depending on the screen
you're on. Its not quite complete and I haven't worked on it in a good while
and don't really consider it done, but I can get the code up somewhere in a
little while.

Some of the things I've done with it is bind all of gud and wanderlust to a
single elscreen. You can bind by path so all files in a subtree are on a
screen. I'm at the dentist now so I'll get to putting the code up later.
>
> Not yet quite satisfied unfortunately.
> Using different desktops for different projects is a neat idea but
> unfortunately not really realistic, I then open too many things and it I
> can't filter with the damn desktop-clear
>
> --8<---------------cut here---------------start------------->8---
> (setq desktop-clear-preserve-buffers
> (append '("\\.newsrc-dribble" "\\.org$" "eternal" "\\*shell\\*"
"\\*group\\*" "\\*ielm\\*") desktop-clear-preserve-buffers))
> --8<---------------cut here---------------end--------------->8---
>
> But this looks correct, at least with that regexp the org files should
> not be killed, but they are, and that takes forever...
>
> I really think that the best way would be to use one desktop for each
> Elscreen.
> But I don't find much to play with in elscreen, and the project is
> kindof dead apparently.
>
> It would be then great to have
> screen 1: project X
> screen 2: project Y
> screen 3: all the rest
>
> Maybe having some rules in ido to hide or at least prioritize some
> buffers.
>
>